1. Field of the Invention
The present invention relates to an upper tool device employed to be attached to a punch press such as a turret punch press and a punch employed in the upper tool device. More specifically, the invention relates to an upper tool device that can facilitate height adjustment.
2. Description of the Related Art
In a conventional upper tool device employed to be attached to a punch press, when a punch blade of the upper tool device is worn, the punch blade is reground. When the punch blade is reground, an entire length of the punch is reduced, and a height adjustment is consequently performed (for example, see Patent document: Japanese Patent Application Laid-open No. 2001-105053).
FIG. 1 shows a configuration of the upper tool device disclosed in the Patent document.
Namely, the conventional upper tool device includes a cylindrical punch guide 101. A punch body 105 that includes a punch blade 103 provided on a lower end thereof is fitted into the punch guide 101 so as to be movable in vertical direction. To restrict rotation of the punch body 105 relative to the punch guide 101, a key 109 provided on the punch body 105 is slidably engaged with a vertical key groove 107 formed in the punch guide 101.
A cylindrical spring collar 111 is detachably attached to an upper portion of the punch guide 101 through a pin 113. A lock member 115 is fixedly screwed with an upper portion of the spring collar 111. A punch head 117 is vertically supported by the lock member 115 so as to be movable in vertical direction, and a screw formed on an upper end of the punch body 105 is screwed with a female screw formed on this punch head 117 so that a vertical position of the punch body 105 is adjustable. A stripper spring 121 is elastically attached between an annular spring seat 119 abuttable with a lower end of the punch head 117 and a bottom of the spring collar 111.
To restrict rotation of the punch head 117 relative to the lock member 115, a vertical groove 123 is formed circumferentially and equidistantly in a plurality of portions on an outer peripheral surface of the punch head 117. A lock piece 127 of a lock unit 125 provided in the lock member 115 is provided to be disengageably engaged with the groove 123. Since a configuration of the lock unit 125 is publicly known, it will not be explained in detail.
With this configuration, while the lock piece 127 is engaged with the groove 123 of the punch head 117, the rotation of the punch head 117 relative to the lock unit 125 is restricted. Therefore, when a vertically movable striker (not shown) provided in a punch press presses the punch head 117, then the punch head 117 and the punch body 105 are moved downward against an urging force of the stopper spring 121, and a workpiece provided on a die (not shown) is punched.
When the punch head 117 is rotated while the lock piece 127 is disengaged from the groove 123 of the punch head 117, the position of the punch body 105 can be vertically adjusted since the rotation of the punch body 105 is restricted by the key 109. As explained above, the punch head 117 is rotated and fixedly screwing of the upper end of the punch body 105 with the punch head 117 is released, whereby the punch body 105 can be detached from the punch guide 101 in a downward direction and the punch blade 103 can be reground.
With the configuration of this conventional upper tool device, when the punch blade 103 is worn, the punch blade 103 can be reground by detaching the punch body 105 from the die assembly (upper tool device) without using a tool. In addition, the height adjustment can be performed.
The conventional upper tool device has, however, the following disadvantages. When the punch head 117 is rotated relative to the punch body 105, the engagement of the key 109 provided on the punch body 105 with the key groove 107 of the punch guide 101 can restrict the rotation of the punch body 105. Therefore, even if the punch blade 103 is, for example, circular to allow the rotation of the punch body 105, it is still necessary to provide the key and the key groove. The conventional upper tool device is, therefore, desired to be improved in facilitation of machining and simplification of the configuration.
Furthermore, with the configuration of the conventional upper tool device, the punch body is inserted into the punch guide from below and the upper end of the punch body is screwed with the punch head. This disadvantageously complicates an assembly operation. In addition, when the punch body is vertically adjusted, it is rather difficult to measure a length from an upper surface of the punch head to the punch blade.